You have a partial clog, probably a grease buildup, an enzyme cleaner may do the trick, pour the entire bottle in overnight. In any case, you need to clean the drain and avoid putting grease into it, and NO, it’s not normal.
Your dual kitchen sink’s drain is connected via a "Y" type connection, with only one pipe leading to the sewer line. If you have a lot of water draining, sometimes the volume that is draining is greater than the capacity of the drain, so some will travel up the other side of the Y connection. It’s nothing to worry about, unless it happens all the time, which may indicate a slow drain (slightly clogged) Maybe time to run some Draino or something down there.
If your drain was real clean this would not happen. Grease and soap build up sometime slow the draining process. Try some vinegar and baking soda to clear it . About a half box of soda followed by one half cup of vinegar. It will smell pleasant as well .Plug both sinks as you do this.
It may or may not be partially clogged. The flow below the y is less than the flow into the y. The pipe from the other side of the sink offers less resistance so the water goes there. If they balance then both empty as fast as say the bath tub, then don’t do anything its normal. If its slow especially leaving residue the vinegar and soda should speed it up.
The dual sink you have has a single trap that leads to a single drain down to the sewer. The trap can be remove and check for accummulated debris. After considerable time, this trap builds up food particles that slowly builds up and clogged your system. You can use some environment friendly chemicals that can be bought over-the-counter, like DRANO or LIQUID SOSA, justa ask for it. If this is not enough, try to unscrew the trap and clean it.